The gold mine actually exists, an impressive one kilometre tunnel with railway that cost several million pounds to build and develop together with all the sample drill-core and test results that are vital to prove an economic resource.

"Imagine our surprise to discover not only a fossil bloom of bacteria that make iron-oxide magnets within their cells, but also an entirely unknown set of organisms that grew magnetic crystals to giant sizes," said Caltech postdoctoral scholar Timothy Raub, who collected the samples from an International Ocean Drilling Program drill-core storehouse at Rutgers University in New Jersey.